John pienry darby



(No Model.)

J. H. DARBY.

PROCESS OF REGARBONIZING STEEL.

No. 406,430. Patented July 9, 1889.

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UNITED STATES PATENT OFFICE.

JOHN HENRY DARBY, OF BRYMBO, COUNTY OF DENBIGH, ASSIGNOR TO. PERCY CARLYLE GILOIIRIST, OF LONDON, ENGLAND.

PROCESS OF RECARBONIZING STEEL.

SPECIFICATION forming part of Letters Patent No. 406,430, dated July 9, 1889.

Application filed lngus' 14,1888. Serial No. 282.709. (N model.)

To all 1077,0111. it may concern.-

Be it known that I, JOHN HENRY DARBY, a subject of Her Majesty the Queen of Great Britain, residing at Brymbo, in the county of Denbigh, England, have invented certain new and useful Improvements in the Process of Recarbonizing of Steel; and I do hereby declare that the following is a full, clear, and

. exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

In the manufacture of ingot iron and steel it is common to first purify the crude metal either in a Bessemer converter, open-hearth or other furnace, and thereby eliminate the carbon in the crude metal, which has to be restored to a greater or less extent by some subsequent process.

The object of my invention is to effect this recarburizing of the mass of molten metal thus purified by means of charcoal or other carbonaceous matter, as coke, anthracite coal, or other suitable form of carbon; and to this end my invention consists in the process hereinafter set forth of converting crude iron into ingot iron or steel by first purifying the crude metal, and then passing the same while still molten to and through a mass of carbonaceous material.

In order that the invention may be clearly understood, reference is made to the accompanying drawing, which forms part of this specification.

The metal to be treated from either a Bessemer converter, open-hearth furnace, or crucible is poured into the usual ladle A, which is fitted with an ordinary stopper and nozzle. The ladle being brought into position, the stopper is lifted and the metal allowed to flow through the vessel B, which is lined with good refractory material, and contains charcoal or other suitable form of carbog. As the metal passes or filters through this it dissolves or takes up carbon and passes outof the vessel or filter B through a perforated fire-clay plate b, and is retained in the ladle O, which is also fitted with a stopper and nozzle d for casting purposes.

It is found that the steel takes up carbon in passing or filtering through the carbonaceous material, and I judge by experiment that a vessel or filter about four feet long and eighteen inches in diameter, if nearly filled with charcoal or gas carbon, (particularly the former,) will give good results when dealing with a five to ten ton charge of metal.

To regulate the percentage of carbon in the final steel, the capacity of the apparatus for carburizin g must be determinedthatis, supposing it is found to introduce one per cent. of carbon, then to produce steel containing .5 per cent. carbon, working with a ten-ton charge, I would prefer to run five tons of the soft decarburized metal into the ladle O first, and the remaining five tons through the Vessel or filter B into the same ladle, thus obtaining the percentage of carbon required in the finished steel. When ladle O has received its entire charge, it may be lifted up by a hydraulic ram D or other device and run over the molds into which the metal is to be cast.

hat I claim as my invention, and desire to secure by Letters Patent, is-

The herein-described process of converting crude iron into ingot iron or steel, the same consisting in first purifying the crude metal, and then passing the same while still molten to and through a mass of carbonaceous material.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

' JOHN HENRY DARBY. Nitnesses:

ALLEN P. J ONES,

WALTER J. SKERTEN. 

